Fix FS#11007: Lua didn't parse negative numbers correct when reading from files

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@24632 a1c6a512-1295-4272-9138-f99709370657

4 files changed, 297 insertions, 13 deletions

diff --git a/apps/plugins/lua/SOURCES b/apps/plugins/lua/SOURCES
index d475783..7354fdc 100644
--- a/apps/plugins/lua/SOURCES
+++ b/apps/plugins/lua/SOURCES
@@ -29,6 +29,7 @@ lzio.c
 rockaux.c
 rocklib.c
 rockmalloc.c
+fscanf.c
 gmtime.c
 strcspn.c
 strftime.c
diff --git a/apps/plugins/lua/fscanf.c b/apps/plugins/lua/fscanf.c
new file mode 100644
index 0000000..25058af
--- /dev/null
+++ b/apps/plugins/lua/fscanf.c
@@ -0,0 +1,290 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copied from firmware/common/sscanf.c
+ * Original author: Tomasz Malesinski
+ *
+ * Copyright (C) 2010 Maurus Cuelenaere
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+
+#include "rocklibc.h"
+
+static int parse_dec(int (*peek)(void *userp),
+                     void (*pop)(void *userp),
+                     void *userp,
+                     long *vp)
+{
+    long v = 0;
+    int n = 0;
+    int minus = 0;
+    char ch;
+
+    if ((*peek)(userp) == '-')
+    {
+        (*pop)(userp);
+        n++;
+        minus = 1;
+    }
+
+    ch = (*peek)(userp);
+    if (!isdigit(ch))
+        return -1;
+
+    do
+    {
+        v = v * 10 + ch - '0';
+        (*pop)(userp);
+        n++;
+        ch = (*peek)(userp);
+    } while (isdigit(ch));
+
+    *vp = minus ? -v : v;
+    return n;
+}
+
+static int parse_chars(int (*peek)(void *userp),
+                       void (*pop)(void *userp),
+                       void *userp,
+                       char *vp,
+                       bool fake)
+{
+    int n = 0;
+
+    char *pt=vp;
+
+    while (!isspace((*peek)(userp)))
+    {
+        if(fake==false)
+            *(pt++) = (*peek)(userp);
+
+        n++;
+        (*pop)(userp);
+    }
+
+    if(fake==false)
+        (*pt)='\0';
+
+    return n;
+}
+
+static int parse_hex(int (*peek)(void *userp),
+                     void (*pop)(void *userp),
+                     void *userp,
+                     unsigned long *vp)
+{
+    unsigned long v = 0;
+    int n = 0;
+    char ch;
+
+    ch = (*peek)(userp);
+    if (!isxdigit(ch))
+        return -1;
+
+    do
+    {
+        if (ch >= 'a')
+            ch = ch - 'a' + 10;
+        else if (ch >= 'A')
+            ch = ch - 'A' + 10;
+        else
+            ch = ch - '0';
+        v = v * 16 + ch;
+        (*pop)(userp);
+        n++;
+        ch = (*peek)(userp);
+    } while (isxdigit(ch));
+
+    *vp = v;
+    return n;
+}
+
+static int skip_spaces(int (*peek)(void *userp),
+                       void (*pop)(void *userp),
+                       void *userp)
+{
+    int n = 0;
+    while (isspace((*peek)(userp))) {
+        n++;
+        (*pop)(userp);
+    }
+    return n;
+}
+
+static int scan(int (*peek)(void *userp),
+                void (*pop)(void *userp),
+                void *userp,
+                const char *fmt,
+                va_list ap)
+{
+    char ch;
+    int n = 0;
+    int n_chars = 0;
+    int r;
+    long lval;
+    bool skip=false;
+    unsigned long ulval;
+
+    while ((ch = *fmt++) != '\0')
+    {
+        bool literal = false;
+
+        if (ch == '%')
+        {
+            ch = *fmt++;
+
+            if(ch== '*')  /* We should process this, but not store it in an argument */
+            {
+                ch=*fmt++;
+                skip=true;
+            }
+            else
+            {
+                skip=false;
+            }
+
+            switch (ch)
+            {
+                case 'x':
+                    n_chars += skip_spaces(peek, pop, userp);
+                    if ((r = parse_hex(peek, pop, userp, &ulval)) >= 0)
+                    {
+                        if(skip==false)
+                        {
+                            *(va_arg(ap, unsigned int *)) = ulval;
+                            n++;
+                        }
+                        n_chars += r;
+                    }
+                    else
+                        return n;
+                    break;
+                case 'd':
+                    n_chars += skip_spaces(peek, pop, userp);
+                    if ((r = parse_dec(peek, pop, userp, &lval)) >= 0)
+                    {
+                        if(skip==false)
+                        {
+                            *(va_arg(ap, int *)) = lval;
+                            n++;
+                        }
+                        n_chars += r;
+                    }
+                    else
+                        return n;
+                    break;
+                case 'n':
+                    if(skip==false)
+                    {
+                        *(va_arg(ap, int *)) = n_chars;
+                        n++;
+                    }
+                    break;
+                case 'l':
+                    n_chars += skip_spaces(peek, pop, userp);
+                    ch = *fmt++;
+                    switch (ch)
+                    {
+                        case 'x':
+                            if ((r = parse_hex(peek, pop, userp, &ulval)) >= 0)
+                            {
+                                if(skip==false)
+                                {
+                                    *(va_arg(ap, unsigned long *)) = ulval;
+                                    n++;
+                                }
+                                n_chars += r;
+                            }
+                            else
+                                return n;
+                            break;
+                        case 'd':
+                            if ((r = parse_dec(peek, pop, userp, &lval)) >= 0)
+                            {
+                                if(skip==false)
+                                {
+                                    *(va_arg(ap, long *)) = lval;
+                                    n++;
+                                }
+                                n_chars += r;
+                            }
+                            else
+                                return n;
+                            break;
+                        case '\0':
+                            return n;
+                        default:
+                            literal = true;
+                            break;
+                    }
+                    break;
+                case 's':
+                    n_chars += skip_spaces(peek, pop, userp);
+                    n_chars += parse_chars(peek,pop, userp,skip?0:va_arg(ap, char *), skip );
+                    if(skip==false)
+                    {
+                        n++;
+                    }
+                    break;
+                case '\0':
+                    return n;
+                default:
+                    literal = true;
+                    break;
+            }
+        } else
+            literal = true;
+
+        if (literal)
+        {
+            n_chars += skip_spaces(peek, pop, userp);
+            if ((*peek)(userp) != ch)
+                continue;
+            else
+            {
+                (*pop)(userp);
+                n_chars++;
+            }
+        }
+    }
+    return n;
+}
+
+static int fspeek(void *userp)
+{
+    int fd = (int) userp;
+    char buf = 0;
+    if(rb->read(fd, &buf, 1) == 1)
+        rb->lseek(fd, -1, SEEK_CUR);
+    return buf;
+}
+
+static void fspop(void *userp)
+{
+    rb->lseek((int) userp, 1, SEEK_CUR);
+}
+
+int PREFIX(fscanf)(int fd, const char *fmt, ...)
+{
+    int r;
+    va_list ap;
+
+    va_start(ap, fmt);
+    r = scan(fspeek, fspop, (void*) fd, fmt, ap);
+    va_end(ap);
+    return r;
+}
diff --git a/apps/plugins/lua/liolib.c b/apps/plugins/lua/liolib.c
index eea40c0..e50524a 100644
--- a/apps/plugins/lua/liolib.c
+++ b/apps/plugins/lua/liolib.c
@@ -245,24 +245,13 @@ static int io_lines (lua_State *L) {
 ** =======================================================
 */
 
-
 static int read_number (lua_State *L, int *f) {
-  char buf[10]; /* Maximum uint32 value is 10 chars long */
   lua_Number d;
-  int i = 0;
-  /* Rather hackish, but we don't have fscanf.
-     Was: fscanf(f, LUA_NUMBER_SCAN, &d); */
-  memset(buf, 0, 10);
-  rb->read(*f, buf, 10);
-  while(isdigit(buf[i]) && i < 10)
-    i++;
-  if(i == 0) return 0;
-  else {
-    rb->lseek(*f, i-10, SEEK_CUR);
-    d = rb->atoi(buf);
+  if (PREFIX(fscanf)(*f, LUA_NUMBER_SCAN, &d) == 1) {
     lua_pushnumber(L, d);
     return 1;
   }
+  else return 0;  /* read fails */
 }
 
 
diff --git a/apps/plugins/lua/rocklibc.h b/apps/plugins/lua/rocklibc.h
index 78b83a6..9b68f42 100644
--- a/apps/plugins/lua/rocklibc.h
+++ b/apps/plugins/lua/rocklibc.h
@@ -28,10 +28,12 @@
 
 #ifdef SIMULATOR
 #include <errno.h>
+#define PREFIX(_x_) sim_ ## _x_
 #else
 extern int errno;
 #define EINVAL          22      /* Invalid argument */
 #define ERANGE          34      /* Math result not representable */
+#define PREFIX
 #endif
 
 #define __likely   LIKELY
@@ -41,5 +43,7 @@ extern int errno;
 #define memcmp rb->memcmp
 #define strlen rb->strlen
 
+extern int PREFIX(fscanf)(int fd, const char *fmt, ...);
+
 #endif /* _ROCKLIBC_H_ */